C. elegans, like humans, experience cognitive functional declines with age, but the cause of these declines are not yet known. We propose to identify age-related changes in neuronal function, and to distinguish those changes that are functionally deleterious from those that may be an adaptive response to aging. In our first Aim, we will identify the genes required for long-term associative memory (LTAM) that change with age and with decreased function, and rescue function with age through manipulation of candidate genes. Our second Aim focuses on the identification of the cells involved in LTAM, and the characterization of their roles in the LTAM process. Furthermore, we will assess changes in cellular function with age. Finally, we will compare changes during normal aging to pathological changes in two C. elegans models of dementia. Comparisons with models of dementia will distinguish healthy from pathological age-dependent changes. Through these studies, the contributions of specific components to functional cognition will be used to identify the best targets of therapeutic intervention to treat cognitive decline with age. PUBLIC HEALTH RELEVANCE: In our work, we propose to use the model organism C. elegans to discover genes whose changes in function are correlated with decline in cognitive ability with age. We have designed a test of long-term memory in this organism, and observe that the animals lose their ability to remember with age. Using this test and various molecular tools, we can study the genes and cells responsible for loss of memory with age and in neurodegenerative disease.